<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>内部函数</title>
    <script type="text/javascript">
    //定义函数(无参数，也无返回值)
    function Abc(){
        document.writeln("无参数，也无返回值");
    }

    //直接调用
    //Abc();
    </script>
</head>
<body>
    <!-- 在表单中调用 -->
    <input type="button" value="确认" onclick="Abc()" />

    <input type="text" onchange="Abc()" />
</body>
</html>